The big for 2020 was when Adventureland post this on May 17, 2020 to their Facebook page:
The image of a knight slaying a dragon immediately started speculation that something would be happening to the double-loop Dragon coaster.
Two days later, on May 19, the park posted an animated GIF that has the same image rotating in to view with the text “The Dragon Slayer” above it:
Facebook group member Alec Rushford posted that SkyHigh Coasters LLC had reshared the teaser on their Facebook page, with Tag Gable following up with a post saying that they were the ones that did the build job on last year’s Phoenix roller coaster.
Also on May 19, local TV station KCCI posted an article that included drone footage of the Dragon being dismantled at the park:
That post was quickly removed from the page, but said a zoomed photo taken off property confirms this was actually happening.
As of this posting, it looks like the park will have two rides less for the 2020 season, with something new to replace the Dragon next year. Nothing has been announced about a replacement for the Splash Over (though some have speculated maybe it is just being disassembled to be refurbished and will return).